1. Technical Field
The present invention relates to a target supply device, a target material refining method, a recording medium having target material refining program recorded therein, and a target generator.
2. Related Art
In recent years, semiconductor production processes have become capable of producing semiconductor devices with increasingly fine feature sizes, as photolithography has been making rapid progress toward finer fabrication. In next generation of semiconductor production processes, microfabrication with feature sizes of 45 to 70 nm, and further, microfabrication with feature sizes of 32 nm or less will be required. In order to meet the demand for microfabrication with feature sizes of 32 nm or less, for example, an exposure apparatus is needed in which an apparatus for generating extreme ultraviolet (EUV) light at a wavelength of approximately 13 nm is combined with a reduced projection reflective optical system.
Three kinds of apparatuses for generating EUV light are known in general, which include a Laser Produced Plasma (LPP) type apparatus in which plasma generated by irradiating a target material with a laser beam is used, a Discharge Produced Plasma (DPP) type apparatus in which plasma generated by electric discharge is used, and a Synchrotron Radiation (SR) type apparatus using synchrotron radiation.